code: def test_avg_aggregation(
      consistent_id_object_repository: ConsistentIdObjectRepository,
      simple_semantic_manifest_lookup: SemanticManifestLookup,
  ) -> None:
      """Checks for function expression handling for average_booking_value, an AVG type metric in the simple model."""
      measure_name = "average_booking_value"
      instance_set = __get_filtered_measure_instance_set(
          "bookings_source",
          measure_name,
          consistent_id_object_repository,
      )
  
      select_column_set: SelectColumnSet = (
          CreateSelectColumnsWithMeasuresAggregated(
              __SOURCE_TABLE_ALIAS,
              DunderColumnAssociationResolver(
                  simple_semantic_manifest_lookup
              ),
              simple_semantic_manifest_lookup.semantic_model_lookup,
              (
                  MetricInputMeasureSpec(
                      measure_spec=MeasureSpec(
                          element_name="average_booking_value"
                      )
                  ),
              ),
          ).transform(instance_set=instance_set)
      )
  
      assert len(select_column_set.measure_columns) == 1
      measure_column = select_column_set.measure_columns[0]
      expr = measure_column.expr
      assert isinstance(expr, SqlAggregateFunctionExpression)
      assert expr.sql_function == SqlFunction.AVERAGE
  
file_path: metricflow/metricflow/test/plan_conversion/instance_converters/test_create_select_columns_with_measures_aggregated.py
imports: from __future__ import annotations
  from metricflow.instances import InstanceSet
  from metricflow.model.semantic_manifest_lookup import SemanticManifestLookup
  from metricflow.plan_conversion.column_resolver import DunderColumnAssociationResolver
  from metricflow.plan_conversion.instance_converters import CreateSelectColumnsWithMeasuresAggregated, FilterElements
  from metricflow.plan_conversion.select_column_gen import SelectColumnSet
  from metricflow.specs.specs import InstanceSpecSet, MeasureSpec, MetricInputMeasureSpec
  from metricflow.sql.sql_exprs import SqlAggregateFunctionExpression, SqlFunction, SqlPercentileExpression
  from metricflow.test.fixtures.model_fixtures import ConsistentIdObjectRepository
label_desc: Use image node_id 4 for calling a global function with example usage: test_avg_aggregation(consistent_id_object_repository, simple_semantic_manifest_lookup) without return types